Remember those stories last week about a record-setting, scary-sounding dry spell for the combined months of January and February? You’ll forget all about them if we see a series of storms this month and next.
The record dry time is actually in the Northern Sierra, the most important watershed in the state, as my Sacramento Bee colleague Matt Weiser wrote. That snowpack melts into the state’s biggest reservoirs.
But the Northern Sierra is actually in better shape than it was at this time last year. So is the Southern Sierra. The snow from the big storms in November and December is mostly still up there. It hasn’t melted.
The huge reservoirs in Northern California — Shasta, Oroville, Trinity — are all holding an above-average amount of water right now. We’re not hearing anything yet about water restrictions in the Bay Area.
The real concern is San Luis in western Merced County, where west San Joaquin Valley farmers get water.
It is not a mountain reservoir. It does not have a big, natural stream, unlike the reservoirs I’ve mentioned. It is one of the larger off-stream reservoirs you will find anywhere in the United States.
So, water must be pumped into San Luis from the Sacramento-San Joaquin River Delta, 120 miles away. The delta pumping has been limited to protect the dwindling delta smelt. So it San Luis only at 69% of average right now.
The reservoir is 2 million acre-feet — about four times bigger than Millerton Lake, though it’s not all devoted to the Central Valley Project. The state stores water there, too.
Many experts tell me they don’t think it will fill.
There are bigger questions now, because pumping for San Luis usually continues well into the warm season to provide water. To provide enough water, the reservoir needs to get continuous pumping from the delta in spring.
What if the weather stays dry? What if the pumping restrictions continue at the delta? How much water will be available in May and June when the thermometer starts to climb?
Should farmers fallow a lot of acreage? Should they drill new wells and keep pulling water from the ground?